The present invention is directed to contulakin-G (which is the native glycosylated peptide), a des-glycosylated contulakin-G (termed Thr10-contulakin-G), and derivatives thereof, to a cDNA clone encoding a precursor of this mature peptide and to a precursor peptide. The invention is further directed to the use of this peptide as a therapeutic for anti-seizure, anti-inflammatory, anti-shock, anti-thrombus, hypotensive, analgesia, anti-psychotic, Parkinson""s disease, gastrointestinal disorders, depressive states, cognitive dysfunction, anxiety, tardive dyskinesia, drug dependency, panic attack, mania, irritable bowel syndrome, diarrhea, ulcer, GI tumors, Tourette""s syndrome, Huntington""s chorea, vascular leakage, anti-arteriosclerosis, vascular and vasodilation disorders, as well as neurological, neuropharmalogical and neuropsychopharmacological disorders.
The publications and other materials used herein to illuminate the background of the invention, and in particular, cases to provide additional details respecting the practice, are incorporated by reference, and for convenience are numerically referenced in the following text and respectively grouped in the appended bibliography.
Mollusks of the genus Conus produce a venom that enables them to carry out their unique predatory lifestyle. Prey are immobilized by the venom that is injected by means of a highly specialized venom apparatus, a disposable hollow tooth that functions both in the manner of a harpoon and a hypodermic needle.
Few interactions between organisms are more striking than those between a venomous animal and its envenomated victim. Venom may be used as a primary weapon to capture prey or as a defense mechanism. Many of these venoms contain molecules directed to receptors and ion channels of neuromuscular systems.
Several peptides isolated from Conus venoms have been characterized. These include the xcex1-, xcexc- and -conotoxins which target nicotinic acetylcholine receptors, muscle sodium channels, and neuronal calcium channels, respectively (Olivera et al., 1985). Conopressins, which are vasopressin analogs, have also been identified (Cruz et al., 1987). In addition, peptides named conantokins have been isolated from Conus geographus and Conus tulipa (Mena et al., 1990; Haack et al., 1990). These peptides have unusual age-dependent physiological effects: they induce a sleep-like state in mice younger than two weeks and hyperactive behavior in mice older than 3 weeks (Haack et al., 1990). The isolation, structure and activity of K-conotoxins are described in U.S. Pat. No. 5,633,347. Recently, peptides named contryphans containing D-tryptophan residues have been isolated from Conus radiatus (U.S. Ser. No. 09/061,026), and bromo-tryptophan conopeptides have been isolated from Conus imperialis and Conus radiatus (U.S. Ser. No. 08/785,534).
It is desired to identify additional conopeptides having activities of the above conopeptides, as well as conotoxin peptides having additional activities.
The present invention is directed to contulakin-G (which is the native glycosylated peptide), a des-glycosylated contulakin-G (termed Thr10-contulakin-G), and derivatives thereof, to a cDNA clone encoding a precursor of this mature peptide and to a precursor peptide. The invention is further directed to the use of this peptide as a therapeutic for anti-seizure, anti-inflammatory, anti-shock, anti-thrombus, hypotensive, analgesia, anti-psychotic, Parkinson""s disease, gastrointestinal disorders, depressive states, cognitive dysfunction, anxiety, tardive dyskinesia, drug dependency, panic attack, mania, irritable bowel syndrome, diarrhea, ulcer, GI tumors, Tourette""s syndrome, Huntington""s chorea, vascular leakage, anti-arteriosclerosis, vascular and vasodilation disorders, as well as neurological, neuropharmacological and neuropsychopharmacological disorders.
In one embodiment, the present invention is directed to contulakin-G, contulakin-G propeptide and nucleic acids encoding this peptide. The contulakin-G has the following formula:
Xaa1-Ser-Glu-Glu-Gly-Gly-Ser-Asn-Ala-Thr-Lys-Lys-Xaa2-Tyr-Ile-Leu (SEQ ID NO:1)
where Xaa1 is pyro-Glu, Xaa2 is proline or hydroxyproline and Thr10 is modified to contain an O-glycan. X2 is preferably proline. In accordance with the present invention, a glycan shall mean any N-, S- or O-linked mono-, di-, tri-, poly- or oligosaccharide that can be attached to any hydroxy, amino or thiol group of natural or modified amino acids by synthetic or enzymatic methodologies known in the art. The monosaccharides making up the glycan can include D-allose, D-altrose, D-glucose, D-mannose, D-gulose, D-idose, D-galactose, D-talose, D-galactosamine, D-glucosamine, D-N-acetyl-glucosamine (GlcNAc), D-N-acetyl-galactosamine (GalNAc), D-fucose or D-arabinose. These saccharides may be structurally modified as described herein, e.g., with one or more O-sulfate, O-phosphate, O-acetyl or acidic groups, such as sialic acid, including combinations thereof The gylcan may also include similar polyhydroxy groups, such as D-penicillamine 2,5 and halogenated derivatives thereof or polypropylene glycol derivatives. The glycosidic linkage is beta and 1-4 or 1-3, preferably 1-3. The linkage between the glycan and the amino acid may be alpha or beta, preferably alpha and is 1-. Preferred glycans are described further herein, with the most preferred glycan being Gal(xcex21xe2x86x923)GalNAc(xcex11xe2x86x92).
In a second embodiment, the present invention is directed to a generic contulakin-G having the following general formula,
Xaa1-Xaa2-Xaa3-Xaa3-Gly-Gly-Xaa2-Xaa4-Xaa5-Xaa6-Xaa7-Xaa8-Xaa9-Xaa10-Ile-Leu (SEQ ID NO:2),
where Xaa1 is pyro-Glu, Glu, Gln or xcex3-carboxy-Glu; Xaa2 is Ser, Thr or S-glycan modified Cys; Xaa3 is Glu or xcex3-carboxy-Glu; Xaa4 is Asn, N-glycan modified Asn or S-glycan modified Cys; Xaa5 is Ala or Gly; Xaa6 is Thr, Ser, S-glycan modified Cys, Tyr or any unnatural hydroxy containing amino acid (such as 4-hydroxymethyl-Phe, 4-hydroxyphenyl-Gly, 2,6-dimethyl-Tyr, 3-nitro-Tyr and 5-amino-Tyr); Xaa7 is Lys, N-methyl-Lys, N,N-dimethyl-Lys, N,N,N-trimethyl-Lys, Arg, omithine, homoarginine or any unnatural basic amino acid (such as N-1-(2-pyrazolinyl)-Arg); Xaa8 is Ala, Gly, Lys, N-methyl-Lys, N,N-dimethyl-Lys, N,N,N-trimethyl-Lys, Arg, ornithine, homoarginine, any unnatural basic amino acid (such as N-1-(2-pyrazolinyl)-Arg) or X-Lys where X is (CH2)n, phenyl, xe2x80x94(CH2)mxe2x80x94(CHxe2x95x90CH)xe2x80x94(CH2)mH or xe2x80x94(CH2)mxe2x80x94(Cxe2x95x90C)xe2x80x94(CH2)mH in which n is 1-4 and m is 0-2; Xaa9 is Pro or hydroxy-Pro; and Xaa10 is Tyr, mono-iodo-Tyr, di-iodo-Tyr, O-sulpho-Tyr, O-phospho-Tyr, nitro-Tyr, Trp, D-Trp, bromo-Trp, bromo-D-Trp, chloro-Trp, chloro-D-Trp, Phe, L-neo-Trp, any unnatural aromatic amino acid (such as nitro-Phe, 4-substituted-Phe wherein the substituent is C1-C3 alkyl, carboxyl, hyrdroxymethyl, sulphomethyl, halo, phenyl, xe2x80x94CHO, xe2x80x94CN, xe2x80x94SO3H and xe2x80x94NHAc, 2,6-dimethyl-Tyr and 5-amino-Tyr). The C-terminus contains a free carboxyl group, is amidated is acylated, contains a glycan or contains an aldehyde. It is preferred that the C-terminus contains a free carboxyl. This peptide may further contain one or more glycans as described above. The glycans may occur at residues 2, 7, 8, 10 and 16. The above and other unnatural basic amino acids, unnatural hydroxy containing amino acids or unnatural aromatic amino acids are described in Building Block Index, Version 2.2, incorporated herein by reference, by and available from RSP Amino Acid Analogues, Inc., Worcester, Mass.
In a third embodiment, the present invention is directed to analogs of contulakin-G or the generic contulakin-G. These analogs include N-terminal truncations of contulakin-G or the generic contulakin-G up to and including Thr10. When the N-terminal truncation is through Thr10, Lys11 is N-glycosylated using a carboxylated modified linker. This N-glycosylated Lys11 can be represented as shown in FIG. 1 (Toth et al., 1999), in which R2, R3 and R4 are as described herein. In these truncations, it is preferred that the residue proximal to the truncation is substituted with a glycosylated serine. Additional analogs include peptides in which Ser-O-glycan, Thr-O-glycan or Cys-S-glycan is substituted for a residue at position 1-9.
In a fourth embodiment, the present invention is directed to uses of the peptides described herein as a therapeutic for anti-seizure, anti-inflammatory, anti-shock, anti-thrombus, hypotensive, analgesia, anti-psychotic, Parkinson""s disease, gastrointestinal disorders, depressive states, cognitive dysfunction, anxiety, tardive dyskinesia, drug dependency, panic attack, mania, irritable bowel syndrome, diarrhea, ulcer, GI tumors, Tourette""s syndrome, Huntington""s chorea, vascular leakage, anti-arteriosclerosis, vascular and vasodilation disorders, as well as neurological, neuropharmacological and neuropsychopharmacological disorders. In one aspect of this embodiment, analgesia is induced in a mammal using one of the peptides described herein. In a second aspect of this embodiment, epilepsy or convulsions are treated in a mammal. In a third aspect of this embodiment, schizophrenia is treated in an mammal. In a fourth aspect of this embodiment, tardive dyskinesia and acute dystonic reactions are treated in a mammal. In a fifth aspect of this embodiment, inflammation is treated in a mammal.